U.S. patent application number 10/340700 was filed with the patent office on 2003-08-14 for fluid level measuring device.
Invention is credited to Dougherty, John Michael, Marek, Steven, Schmidt, Michael H., Slabaugh, Karen S..
Application Number | 20030150125 10/340700 |
Document ID | / |
Family ID | 23363906 |
Filed Date | 2003-08-14 |
United States Patent
Application |
20030150125 |
Kind Code |
A1 |
Dougherty, John Michael ; et
al. |
August 14, 2003 |
Fluid level measuring device
Abstract
A fluid level measuring device, also referred to as a dipstick,
for measuring the fluid level in a fluid reservoir or tank, such as
an oil pan or transmission reservoir in an internal combustion
engine. The fluid level measuring device includes a stationary tube
onto which lugs can be directly attached. The dipstick assembly
includes a fluid level indicator measuring blade attached to an
elongated shaft that is molded into a plastic handle assembly. The
plastic handle assembly includes a bayonet type locking mechanism
for locking the handle to the stationary tube assembly. A
compressible seal forms a pressurized seal between the stationary
tube assembly and the handle.
Inventors: |
Dougherty, John Michael;
(Clark, MO) ; Marek, Steven; (Moberly, MO)
; Schmidt, Michael H.; (Moberly, MO) ; Slabaugh,
Karen S.; (Columbia, SC) |
Correspondence
Address: |
ORSCHELN MANAGEMENT CO
2000 US HWY 63 SOUTH
MOBERLY
MO
65270
US
|
Family ID: |
23363906 |
Appl. No.: |
10/340700 |
Filed: |
January 9, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60347490 |
Jan 9, 2002 |
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Current U.S.
Class: |
33/722 |
Current CPC
Class: |
G01F 23/04 20130101 |
Class at
Publication: |
33/722 |
International
Class: |
G01F 023/04 |
Claims
The following is claimed:
1. A fluid measuring apparatus comprising: a shaft comprising first
and second ends and wherein a fluid level indicator blade is
associated with a first end of the shaft or said first end of the
shaft comprises a fluid level indicator, a tube with an open end
for receiving at least one end of the shaft and wherein said
coupler has at least one lug directly connected to the tube, a
handle associated with the second end of the shaft and comprising
at least one slot that comprises an axial portion generally aligned
with the direction of insertion of the shaft into the tube and a
generally transverse portion, wherein one end of said at least one
slot is open and dimensioned to engage said at least one lug and
another end of said slot terminates in a locking seat, and; a seal
associated with the handle that engages at least the open end face
of the coupler when said lug engages said locking seat.
2. The apparatus of claim 1 wherein a second end of said tube is
associated with a fitting for engaging a fluid reservoir.
3. The apparatus of claim 1 wherein said at least one lug comprises
an outwardly extending lug.
4. The apparatus of claim 2 wherein said fitting comprises a
threaded fitting.
5. The apparatus of claim 1 wherein said seal comprises a
compressible member that urges the handle and coupler into a locked
position that is achieved when said at least one lug engages the
locking seat and wherein the locking seat has a larger diameter
than said at least one slot.
6. A fluid measuring apparatus for an engine or a transmission
reservoir comprising: a wire shaft comprising first and second ends
wherein said first end of the shaft is connected to a fluid level
indicator, a non-linear tube comprising a first end having at least
one lug with an enlarged end portion, and a second end of the tube
comprising a fitting for engaging the reservoir, a handle connected
to the second end of the shaft and comprising at least one
curvilinear slot that terminates in a locking seat having an
enlarged diameter relative to the at least one slot, wherein one
end of said at least one slot is open and dimensioned to engage
said at least one lug, and; a seal connected to the handle that
engages at least the open end face of the tube.
7. The apparatus of claim 6 wherein said at least one lug comprises
an outwardly extending lug.
8. The apparatus of claim 6 wherein the shaft is rotatable relative
to the handle.
9. The apparatus of claim 6 wherein the tube comprises a knurled
region that contacts a coupler and said at least one lug is located
upon the coupler.
10. The apparatus of claim 6 wherein said lugs are connected
directly to said tube and said seal comprises a compressible member
that urges the handle and coupler into a locked position when said
at least one lug engages the locking seat.
11. The apparatus of claim 6 wherein the fitting defines a knurled
region for engaging the tube and defines at least one groove for
engaging an opening into the engine reservoir.
12. A method for making a fluid level indicator comprising:
providing a shaft comprising first and second ends, connecting a
fluid level indicator blade to the first end of the shaft,
providing a tube with an open end for receiving at least one end of
the shaft, connecting at least one lug directly connected to the
tube, connecting a fitting to an interior surface of the tube by
inserting said fitting into the tube and reducing the diameter of
the tube, providing a handle comprising at least one slot,
connecting the second end of the shaft to the handle, and
installing a seal in the base of the handle.
13. The method of claim 12 wherein said connecting at least one lug
directly to the tube comprises welding, installing self-clinching
lugs and drilling and fastening.
14. The method of claim 12 wherein said connecting said shaft to
the handle comprises at least one method selected from the group
consisting of overmolding, pinning or gluing.
15. The method of claim 12 wherein said at least one slot that
comprises an axial portion generally aligned with the direction of
insertion of the shaft into the tube and a generally transverse
portion, wherein one end of said at least one slot is open and
dimensioned to engage said at least one lug and another end of said
slot terminates in a locking seat, and the seal is oriented such
that it engages at least the open end face of the coupler when said
lug engages said locking seat.
Description
[0001] The subject matter herein claims benefit under 35 U.S.C.
119(e) of U.S. patent application Ser. No. 60/347,490, filed on
Jan. 09, 2002 and entitled "Fluid Level Measuring Device"; the
disclosure of which is hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The subject invention is directed to a device used to
measure fluid levels, and more particularly, to dipsticks used to
measure fluid levels by contacting an indicator at one end of the
dipstick into a fluid holding compartment.
BACKGROUND OF THE INVENTION
[0003] It is known to use a fluid measuring device for indicating
the fluid level in a selected fluid holding compartments of
internal combustion engines, transmissions, and other machinery
requiring fluids for lubrication and cooling. Typically, the fluid
measuring device is a dipstick for checking the level of fluid such
as engine or transmission oil, or hydraulic fluid within one of the
many fluid holding compartments in the engine, transmission, or
other machine. The dipstick is normally an elongated indicator that
is slidably located within a conduit or pipe attached to the
engine, transmission, gear box, reservoir or machine in which a
fluid level indication is desired. When the dipstick is fully
inserted into the conduit, one end is immersed into the fluid. When
an actual reading of the fluid level is desired, the other end of
the dipstick is pulled from the conduit thereby removing the entire
dipstick from the conduit to allow the user to read the fluid level
from the one end. The dipstick is then reinserted into the fluid
compartment once the fluid level has been checked.
[0004] Traditional fluid level indicator systems typically consist
of a two piece system with a holding tube and a dipstick. Examples
of conventional dipstick systems are disclosed in U.S. Pat. Nos.
3,371,418; 5,485,681 and 5,829,153; the disclosure of each of which
is hereby incorporated by reference. The holding tubes are
generally fabricated from metal tubing and require various forming
operations including bending, flaring, and machining, followed by
the attachment of a dipstick receptacle. In addition, the dipstick
is fabricated from multiple components including a handle, washer,
cap, rubber stopper, shaft assembly, and a marked spring steel
shaft mechanically joined to a spring steel blade. The actual
assembly of these various components involves multiple assembly
operations requiring costly, time-consuming, and labor intensive
manufacturing steps. Therefore, a simpler design requiring fewer
parts and connections as well as less forming is desirable.
[0005] Engines, transmissions, and machinery designs have become
relatively smaller, more compact, and of less weight than
traditional engines, transmissions, and machinery. Therefore, fluid
level indicator systems must be smaller, more compact, and lighter
weight. Moreover, the fluid access routes or paths through which
the fluid level indicator system accesses the fluid storage
compartments are becoming more complex (more twists and turns as
well as longer runs), smaller, and more compact.
[0006] There is a need in this art for smaller and lighter weight
fluid level indicator systems with improved flexibility. There is
also a need for a fluid level indicator system allowing access to
the fluid compartment while assuring a secure, and in some cases a
sealed closure of the access when fluid level determinations are
not being made and/or additional fluid is not being added. When
employed a sealed closure would prevent unnecessary loss of the
fluids during operation as well as supply level pressurization.
Moreover, a positive indication that the dipstick is securely in
place is desirable.
SUMMARY OF THE INVENTION
[0007] The instant invention solves problems associated with
conventional fluid level measuring systems by providing a fluid
level measuring device comprising a tube having lugs extending
therefrom that engage slots defined in a handle.
[0008] In a first aspect of the invention, the fluid level
measuring device comprises a handle having at least one slot
defined therein and an associated dipstick, a tube having lugs
directly attached to the tube and dimensioned to engage the slotted
handle, and a gasket or grommet associated with the handle. The
lugs on the tube can be inwardly or outwardly extending. When the
lugs engage the slots, the gasket or grommet can urge the handle
and tube into a locked position.
[0009] In one aspect of the invention, the handle associated with a
dipstick that is free to swivel or rotate freely within or relative
to a plastic handle. By being able to rotate (e.g., while being
inserted through a non-liner tube and into an engine component),
the dipstick can accommodate travel along non-liner routes without
binding or being permanently deformed.
[0010] The fluid level measuring device comprises a stationary tube
assembly extending from the fluid compartment in which a dipstick
is disposed. The dipstick typically includes a plastic handle that
is joined (e.g., molded onto, pinned, glued, sonic welded, among
other methods for attachment), to one end of a shaft, such as a
flexible spring steel wire shaft. If desired, a mold release agent
can be applied upon a portion of the shaft in order to prevent the
over-molded handle from permanently bonding to the shaft. A
precision stamped fluid level indicator blade extends from a second
end of the shaft and is preferably attached to the shaft by either
die casting, spin welding, ultrasonic welding, or other bonding
means, or by means of a fitting or other connector. The tube
assembly is normally made of a plastic or metallic material and
optionally with an enlarged end. Lugs extend from the end and
provide a bayonet interconnection between the tube and the handle
assembly by twisting the handle assembly relative to the tube. The
lugs can extend inwardly or outwardly depending upon the design of
the handle, e.g., the handle can be inserted into an enlarged
opening of the stationary tube or about the end of the stationary
tube. This causes inter-engagement of the lugs with slots in the
handle. An engine fitting extends from the tube and serves to guide
the indicator blade to an appropriate location within the fluid
cavity.
[0011] The instant invention also solves problems associated with
conventional manufacturing methods by staking an engine fitting at
the end of the stationary tube associated with the fluid level
measuring device. The tube can be shaped or bent into a wide range
of linear or non-linear configurations. Typically the tube
comprises commercial grade steel.
[0012] A gasket or grommet can act as a pressure lock seal for
sealing the handle to the enlarged end when the lugs are locked in
the slots. This pressure lock seal serves to allow significant
pressurization within the dipstick and oil pan or other chamber the
dipstick is affixed to. The gasket can also urge the bayonet
connection of the handle into a locked position relatively to the
lugs on the stationary tube.
[0013] The bayonet interconnection in unison with the gasket can
supply an actual pressurized seal thereby allowing pressurized
testing of the combustion engine, transmission, or other machinery
without either removal of the dipstick or attempts at sealing the
dipstick. Furthermore, a sealed dipstick allows the combustion
engine, transmission, or other machinery to run at the intended
pressure rather than either below the intended pressure or at the
intended pressure due to an adjustment. The seal and locking
engagement between the handle and enlarged end typically involves a
quarter-turn sealing motion with an improved sealing capability and
a positive lock feature.
[0014] The structure is manufactured from lightweight,
corrosion-resistant, plastic materials such as nylon,
glass-reinforced nylon, steel and steel alloys (e.g., 1008, 1010,
and silicon or aluminum killed draw quality alloys) among other
oil, water and temperature resistant materials. A metallic shaft
can be fabricated from stainless steel, zinc plated, phosphated,
chromated, among other metal treatments to improved corrosion
resistance.
[0015] In one aspect of the invention, the fluid level indicating
system is capable of being in fluid communication with the
combustion engine, transmission, or other machinery to which it is
affixed while maintaining a constant pressurization therein through
an improved method of sealing. Specifically, a seal that is capable
of maintaining several atmospheres (at least 1 to 1.5 atm.) of back
pressure is desirable.
[0016] In another aspect, the invention provides a positive
engaging, yet easy to use, locking arrangement for securely locking
and sealing the dipstick within or over the tube with an easy
motion. It is also desirable that this sealing of the dipstick
within the tube is such that the tube may be pressurized to the
same back pressure as the combustion engine, transmission, or other
machinery. In other aspects of the invention, the locking
arrangement employs a gasket or grommet that releases undesirable
pressure.
[0017] In a further aspect, the invention provides a smaller and
more compact fluid level indicating system which has improved
flexibility for routing of the fluid level indicator system in and
around the complex design of engines, transmissions, and
machinery.
[0018] The instant invention can also be employed as a kit or an
assemblage in order to retrofit existing dipstick systems. When
employed as a retro-fit, the inventive dipstick system provides the
same advantages as if installed as an original equipment
dipstick.
[0019] Regardless of whether the aspects of the invention are
employed along or in combination, the instant invention provides a
more corrosion-resistant, lighter weight, less complex, higher
precision and more cost effective fluid level indicator system.
[0020] Still other advantages and benefits of the invention will
become apparent to those skilled in the art upon a reading an
understanding of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The invention may take physical form in certain parts and
arrangements of parts, certain aspects and method of which will be
described in detail in this specification and illustrated in the
accompanying drawings that form a part hereof. Any dimensions shown
on the Figures are for illustration purposes only, and the
components shown in these Figures can be employed in a wide range
of dimensions and configurations.
[0022] FIG. 1 is a side view of the fluid level measuring device
including the stationary tube assembly with a dipstick inserted
therein having a handle attached to one end thereof;
[0023] FIG. 2 is a top view of the fluid level measuring
device;
[0024] FIG. 3 is a partial sectional view of the fluid measuring
device of FIG. 1;
[0025] FIG. 4 and 5 are front and side elevational views,
respectively, of another sealing gasket;
[0026] FIGS. 6 and 7 are elevational views of further grommet
seals;
[0027] FIG. 8 is an elevational view, in partial cross-section, of
the end of the dipstick assembly using the seal of FIG. 7 received
on the tube assembly; and
[0028] FIG. 9 is an elevational view of the end of the dipstick
assembly incorporating yet another grommet embodiment for sealing
the end of the tube assembly.
[0029] FIG. 10 is an exploded side view of the fluid level
measuring device including the stationary tube assembly with a
dipstick wherein the dipstick handle is inserted within an expanded
end of the stationary tube.
[0030] FIG. 11 is a side view of a shaft that is rotatably mounted
within a handle.
[0031] FIG. 12 is an exploded side view of a fluid level measuring
device that can be retrofit to replace an existing fluid level
measuring assembly.
[0032] FIG. 13 is a side view of the fluid level measuring device
including the stationary tube assembly with a dipstick inserted
therein having a handle attached to one end thereof and a staked
engine fitting at the other end.
[0033] FIG. 14 is a side view of the stationary tube assembly of
FIG. 13 and an associated staked engine fitting.
[0034] FIG. 15 is a side view and cross-sectional drawing of the
stationary tube illustrated in FIGS. 13 and 14.
[0035] FIG. 16 is a side view and cross-sectional drawing of the
engine fitting illustrated in FIGS. 13 and 14.
[0036] FIGS. 17A through C illustrate another aspect of the
invention in an assembled view wherein lugs are attached directly
to the tube.
[0037] FIGS. 18A and B illustrate the handle of the assembly shown
in FIGS. 17A through C.
[0038] FIGS. 19A through E illustrate the tube of the assembly
shown in FIGS. 17A through C.
[0039] FIGS. 20A and B illustrate the lugs shown in FIGS. 17A
through C.
CROSS-REFERENCE TO RELATED PATENTS AND PATENT APPLICATIONS
[0040] The subject matter of the invention is related to copending
U.S. patent application Ser. No. 08/976,781, filed on Nov. 24, 1997
and entitled "Fluid Level Measuring Device", now U.S. Pat. No.
6,314,808 and Ser. No. 09/947,314, filed on Sep. 05, 2001 and as a
continuation of Ser. No. 08/976,781; and Ser. No. 10/172,632, filed
on Jun. 13, 2002, and entitled "Connection System For a Fluid Level
Measuring Device" and Ser. No. 10/261,854, filed on Oct. 01, 2002,
and entitled "Fluid Level Measuring Device". The disclosure of each
of these applications is hereby incorporated by reference.
DETAILED DESCRIPTION
[0041] The instant invention relates to a fluid level measuring
device comprising a tube having lugs extending therefrom that
engage slots defined in a handle. The lugs can be either inwardly
or outwardly extending and are dimensioned to be received within
the slotted handle. The handle is associated with a shaft having a
dipstick for measuring fluid level.
[0042] In a first aspect of the invention, the fluid level
measuring device comprises a handle having at least one slot
defined therein and a shaft having an associated dipstick, a tube
having lugs directly attached to the tube and dimensioned to engage
the slotted handle, and a gasket or grommet associated with the
handle. When the lugs engage the slots, the gasket or grommet can
urge the handle and tube into a locked position.
[0043] One aspect of the instant invention relates to a fluid level
indicator system comprising a handle, a rotatably mounted shaft and
dipstick mounted within the handle, and a stationary tube having an
opening for receiving the handle. The rotatably mounted shaft can
be over-molded by the plastic handle in a manner that permits the
shaft to rotate (or prevents the plastic from permanently bonding
to the shaft). The handle can be received within or around the
stationary tube opening.
[0044] At least a portion of the shaft can be contacted with a
fluid that prohibits the over-molding plastic handle from
permanently bonding to the shaft. While any suitable material can
be employed, examples of suitable materials comprise commercially
available injection mold release agents, oils, lubricants, among
others capable of preventing a permanent bond between the shaft and
over-molded plastic. One material comprises a polymeric carrier
such as an acrylic, urethane or epoxy and heat expandable spheres,
e.g., butane filled thermoplastic shells such as Expancels.RTM.
supplied by Akzo-Nobel. The shaft is, for example, dipped into the
expandable material, and during the handle plastic over molding
process the heated plastic causes the material to expand thereby
preventing the thermoplastic from bonding to the shaft. Any bond
forming between the expandable material and the shaft can be broken
by rotating the shaft. If desired, the fluid can be supplemented or
replaced by using a sleeve or material that is consumed during the
over-molding process. Alternatively, a roller tube or sleeve can be
placed around the shaft such that the over-molding plastic bonds to
the pin while allowing shaft to rotate within the tube.
[0045] Another aspect of the invention relates to an improved
manufacturing method and resultant product wherein the stationary
tube is staked onto an engine fitting (the engine fitting guides
the shaft and indicator blade into a fluid reservoir such as oil,
transmission fluid, among others). Examples of suitable engine
fittings and methods for attaching the same to the tube are
described in the Cross-Reference to Related Patents and Patent
Applications. This method can be employed for manufacturing fluid
level indicators with rotary or stationary shafts. The stationary
tube can have a linear or non-linear configuration, and a wide
range of lengths. Employing a staking operation to affix an engine
fitting onto the stationary tube ensures a fluid tight connection
while reducing assembly costs.
[0046] Referring now to the drawings wherein the showings are for
the purposes of illustrating certain aspects of the invention only
and not for purposes of limiting the invention, the overall
arrangement of such aspects of the fluid level measuring device A
can best be understood by reference to FIGS. 1, 3, and 8-10. As
illustrated therein, the fluid level measuring device A comprises a
stationary tube assembly B with a dipstick assembly C removably and
optionally rotatably disposed therein. Specifically, tube assembly
B is an elongated, hollow guide tube 10 with first and second
spaced ends 12 and 14 having a through passage 16 that communicates
with first and second openings 18 and 20 at the respective first
and second ends.
[0047] The tube assembly B further includes an enlarged diameter
coupler or spout 22 attached to the first end 12 of the guide tube
10. In one aspect, the coupler is joined to the first end 12 of the
guide tube as described herein. The coupler 22 has a small diameter
portion 24, a flare or tapered transition portion 26, and a large
diameter portion 28 at its second end. The small diameter portion
is closely received over the guide tube first end. In one aspect,
the large diameter portion includes a pair of outwardly extending
lugs 30A and 30B that form a portion of a locking assembly to be
described in greater detail below. The coupler is also hollow,
defining a continuous internal cavity that extends from a first or
upper end 32 to a second or lower end 34. The internal cavity is
enlarged at the upper end to accommodate an interconnection between
the shaft and a handle, and, if desired, to provide an orifice for
receiving a spout on a fluid container, such as an oil container.
For example, the spout of a standard quart of oil will fit in this
enlarged upper end. Alternatively, the enlarged upper end may be
dimensioned to receive a different sized oil container. It will be
appreciated, however, that the enlarged upper end will eliminate
use of a funnel in many instances.
[0048] Dipstick assembly C includes a plastic molded handle
assembly 50, an elongated relatively stiff, yet bendable shaft 52
such as the stranded wire rope illustrated in the drawings (e.g.,
FIGS. 3, 8 and 11), and a fluid level indicator blade 54. The shaft
52 is optionally rotatably mounted within plastic molded handle
assembly 50, e.g., the shaft 52 can rotate and flex while being
inserted along the typically non-liner length of the stationary
tube. The handle 50 includes gripping portion 56 connected to a
hollow cylindrical base 58 by a neck 60 of reduced dimension. The
gripping portion preferably has a pair of knobs 62A and 62B
extending outwardly and obliquely from the neck 60. The base 58, on
the other hand, has a pair of slots 64A and 64B defined therein. In
one specific aspect, each slot extends entirely through the base
sidewall and is of a generally curvilinear conformation. The slots
have an opening at one end along lower edge 66 of the base and a
locking seat 68 at the other end of the curvilinear slot. Each of
the curvilinear slots 64A and 64B is defined so as to have an axial
portion aligned approximately with the shaft, and likewise the tube
assembly B, and positioned adjacent the lower edge 66 of the base
58, and a generally transverse portion at the other end of the
slots and in which locking seat 68 is defined. Normally, locking
seat 68 will have a diameter larger than the curvilinear slots. The
locking seat can have any suitable configuration such as circular,
key or slot arrangement, among others.
[0049] The combination of slot 64A and 64B with lugs 30A and 30B
defines a locking mechanism or bayonet type interconnection where
lugs 30A and 30B slide in slots 64A and 64B. Axial insertion of the
handle over the lugs and a quarter turn causes the handle base to
slide over the coupler 22 whereby the lugs 30A and 30B become
positively engaged in corresponding locking seats 68.
[0050] Shaft 52 is provided within assembly 50 in a manner that
achieves a secure interconnection. Fluid level indicator blade 54
is affixed to the other end of the shaft 52 by die casting (or
alternatively, by a staked attachment fitting 70 or other suitable
mechanical connection). The die cast construction eliminates
tolerance stack-up problems associated with prior arrangements,
reduces the number of components, and provides a smooth transition
fitting that does not catch in the guide tube. The indicator blade
54 is typically rounded or pointed at its free end to allow for
easy insertion into the coupler 22, through the guide tube 10, and
through engine fitting 72. The indicator blade also includes
indicia, such as shaded area 74A and arrows 74B and 74C on at least
one of the faces of the blade, for indicating the fluid level when
dipstick assembly C is inserted fully into stationary tube assembly
B that extends from the engine fitting.
[0051] Engine fitting 72 is compression sealed or press fit within
second opening 20 of the guide tube 10. Alternatively, the fit may
be a tight seal, a threaded fitting, or other connector, or the fit
may involve bonding, gluing, molding, or other means of sealably
connecting. A lip 76 prevents engine fitting 72 from complete
insertion into elongated guide tube 10. The opposite end of engine
fitting 72 is attached or bonded to a fluid reservoir or tank, such
as found in an internal combustion engine, where it is desirous to
measure the fluid level within the reservoir. In one specific
aspect, this engine fitting is made of steel and has a serrated
outer surface 78 (although alternatively, the outer surface may be
roughened, knurled, or of other texture).
[0052] With the engine fitting 72 connected to a fluid reservoir
and providing access for dipstick assembly C, the opposite end of
stationary tube assembly B, i.e., the coupler 22, is secured at a
convenient location remote from engine fitting 72. The elongated
through passageway that connects coupler 22 and engine fitting 72
thereby provides access to the fluid in the reservoir via dipstick
assembly C. Specifically, fluid level indicator blade 54 is
inserted through the coupler and guide tube 10 such that the free
end of blade 54 may be immersed into the fluid in the reservoir. It
will be appreciated that since the shaft is bendable and rotatable,
the guide tube can adopt twists and turns along its route and the
dipstick assembly can accommodate the tortuous path. For the blade
54 to be fully inserted, handle 56 can engage and interlock with
coupler 22 and lugs 30A and 30B extending therefrom. Specifically,
lugs 30A and 30B align with the open end of slot 64A and 64B
respectively, whereby the handle is further forced over the coupler
22 resulting in lugs 30A and 30B following the curvilinear shape of
slots 64A and 64B until locked in locking seats 68. The result in
the rotation by approximately 90.degree. of the handle about the
coupler 22 as lugs 30A and 30B move from the axial portion of the
respective slots into the transverse portion and eventually the
locking seat 68.
[0053] A seal 80 (FIG. 3) is located in the base of cavity 82, and
may be glued, bonded or otherwise affixedly seated within the cap.
The seal provides a pressure lock seal when the dipstick assembly
is fully received in the guide tube. This seal has sufficient
elasticity to allow compression of the seal by the coupler 22. This
bayonet type locking arrangement provides assurance that fluid
level indicator blade 54 is properly positioned for accurate fluid
level readings as well as providing a positive lock feature for
assuring that handle 56 is locked to stationary tube assembly B.
Moreover, the seal provides sufficient sealing capabilities to
allow the engine, transmission, or other machinery to reach several
atmospheres (preferably at least 1 to 1.5 atm.) of back pressure
without leakage. In addition, when fully sealed, the seal prohibits
contaminants from entering into the fluid reservoir where system
integrity and reliability would be jeopardized, and prohibits
unnecessary fluid loss from the assembly. When a compressible and
resilient seal is employed, the seal functions to urge the handle
and lugs into a locked position, e.g., locking the bayonet
mechanism compresses the seal which in turn causes the seal to urge
the handle into a locked position relative to the locking lugs.
[0054] In one aspect, the coupler 22 and guide tube 10 are
fabricated from plastics while engine fitting 72 is manufactured of
high heat tolerating metals or plastics. Handle 56 is typically a
molded component to or in which flexible shaft 52 is directly
molded, joined, or otherwise connected. The handle is dimensioned
to overlie or encompass the coupler or spout in its locked position
to prevent contaminants from entering the guide tube. In an
alternative aspect of the invention, described below in connection
with FIG. 10, the handle is inserted into the spout. Moreover, the
use of plastics can reduce corrosive effects and provides an
overall reduction in system weight. Yet another advantage of using
plastic in forming a number of the components is that the system
can be color-coded for ease of use by the customer. Blade 54 is
fabricated from steel or other comparable metals or plastics and is
attached to flexible and rotating shaft 52 by attachment fitting 70
as described above. It will be appreciated, however, that other
suitable materials may be used without departing from the scope and
intent of the subject invention.
[0055] FIGS. 4-5 illustrate another aspect of the subject
invention. In this arrangement, a different configuration grommet
90 is shown. It, too is of annular construction and preferably
includes a series of legs 92 disposed in generally parallel
relation and extending across the entire width of the annular
grommet. That is, the legs are separated by groves 94 so that the
legs extend outwardly a minor dimension on the order of
approximately 0.10 inch. An opposite face of the grommet 96 has a
general planar conformation and fits within the base of the cavity
defined by the handle. Thus, as will be appreciated, the grommet
may be adhesively secured or be appreciated, the grommet may be
adhesively secured or interference fit into the base of the handle
and is adapted to engage against end 32 of the spout. The
alternating legs and grooves on the face of the grommet that
engages the end of the spout prevents a seal from being formed in
this particular version, however, by forming the grommet from an
elastomeric material such as neoprene, the positive locking
capability described in association with the aspects of the
invention illustrated in FIGS. 1-3, 10 and 12 is maintained. That
is, the user encounters a positive lock feel as the lugs enter the
locking seats in the end of the slots. The elastomeric nature of
the grommet serves as an integral portion of the locking function
as the lugs 30 extend through the grooves 64, 66 in the handle.
Engagement is made between the handle and the end of the spout. The
lugs then pass the over-center position in the groove and urge the
handle outwardly while maintaining the compressed relationship and
ensuring a locked condition between the handle and the guide
tube.
[0056] FIGS. 6-8 illustrate yet another version of a seal 100 that
provides all of the same features and benefits of those shown and
described in the earlier embodiments. FIG. 6 and 7 illustrate two
similar grommet seals 100 so that like components will be referred
to by like reference numerals with a primed suffix (') in FIG. 7.
The grommet has an enlarged shoulder 102 at one end that is
received in the base of the handle. The shoulder has an outer
diameter sufficient to engage against the axial end of the spout
and perform the combined sealing and locking function as described
above. In addition, a seal is formed in a radial direction with the
wall of the spout by providing a circumferentially continuous
sealing bead 104 (FIG. 6) or pair of beads 104; 106 (FIG. 7). In
these arrangements, the sealing bead(s) is (are) integrally formed
as a part of the grommet seal to reduce the number of components,
eliminate additional assembly, and provide for an assembly that
meets close tolerance specifications. Thus, as best illustrated in
FIG. 8, once the handle is in the locked and sealed position,
terminal end of the spout is sealed against shoulder 102. In
addition, the seal beads 104, 106 engage the radial inner wall of
the spout to provide an enhanced seal. In these aspects or
arrangements, the seals form an interference fit with the handle.
Thus, the enlarged shoulder 102 is dimensioned to form an
interference fit in the base of the handle in addition to being
sized for engagement with the terminal end of the spout. In
substantially all other respects, these arrangements are identical
to the aspects described above.
[0057] FIG. 9 shows yet another aspect of the invention that
provides both an effective seal and positive locking feature. Here,
the grommet or seal 110 is integrally molded into the handle. The
seal has an annular configuration that extends from the planar
interior base of the handle. The seal is circumferentially
continuous and has a tapered or flared radial outer face 112 that
is dimensioned for sealing engagement with the spout. The tapered
conformation serves the dual purpose of sealing the handle and
spout, as well as providing the positive locking function described
above. When the handle is in the fully locked position, the
terminal end of the spout engages the integrally molded seal in the
base of the cap in an axial direction and the tapered wall 112
sealingly engages the radial inner wall of the spout.
[0058] Referring now to FIG. 10, FIG. 10 illustrates a further
aspect of the invention wherein handle 120 is inserted and lockable
within opening 121 defined in expanded spout 122 on one end of tube
123. Handle 120, as illustrated, includes gripping knobs or areas
120A and 120B (handle 120 can alternatively include the gripping
knobs illustrated in FIG. 8). Handle 120 has the previously
described bayonet connection, except that handle 120 is inserted
within spout 122 and engages locking lugs (not shown) protruding
inwardly from the inner surface of spout 122. As the handle 120 is
inserted into spout 122, a recessed area (not shown) and defined
within shoulder 124 engages gasket 125. Gasket 125 is compressed
against shoulder 124 and the interior base of spout 122 as handle
120 is inserted into spout 122. As handle 120 is inserted into
spout 122 curvilinear channels 126 (having one open end) defined in
side-wall 127 engage inwardly protruding locking lugs on spout 122.
Locking lugs travel along channels 126 until reaching area 128 at
the closed end of channels 126. A recess 129 defined at area 128
functions to secure the locking lugs in a locked position within
channels 126.
[0059] Optionally rotatable dipstick shaft 130 is carried along
with handle 120 as handle 120 is inserted into spout 122. As
described above, the distal end of dipstick shaft 130 has a blade
(not shown) that is employed for measuring a fluid level. Dipstick
shaft 130 is free to flex and rotate as it is inserted into spout
122 and travels along tube 123.
[0060] Referring now to FIG. 11, FIG. 11 illustrates a rotatable
shaft 140 that can be over-molded by a dipstick handle such as
illustrated in FIGS. 1-3 and 8-10. The rotatable shaft 140 is
normally cleaned and polished to have smooth surface thereby
enhancing the ability of shaft 140 to rotate within a dipstick
handle. Shaft 140 has at least two chamfered regions 141A and 141B.
These regions enhance the molding about shaft 140 as well as
prevent shaft 140 from being pulled out of a handle. These regions
can have any desirable configuration such as a flatten or nail head
structure, semi-circular, among other configurations that permit
rotation and prevent pull-out.
[0061] Shaft 140 also includes chamfered region 142. A blade (not
shown) having a fluid level indicator at its distal end is
connected to shaft 140 at chamfered region 142. The attachment can
be achieved by any suitable method such as die-casting, staking,
riveting, welding, among other conventional methods for attaching
elongated metal articles.
[0062] Referring now to FIG. 12, FIG. 12 illustrates a retro-fit
kit that can be employed for replacing conventional dipsticks with
the inventive fluid level indicator. Kit 150 comprises compression
sleeve 151 having threaded area 152 and compressive fitting 153.
Kit 150 further comprises compression nut 154 and stationary tube
member 154. Stationary tube member 154 typically comprises one of
the stationary tubes illustrated in FIGS. 1, 3, and 8-10. The
portion of compressive sleeve 151 in contact with stationary tube
member 154 typically has a diamond knurled surface finish. In order
to install kit 150 as a retrofit for an existing dipstick system,
the existing dipstick system, which comprises the dipstick and the
portion of the stationary tube contacting the existing dipstick, is
removed, e.g., sawing, clipping, among other methods for cutting
metal. Compressive nut 154 is slid over the existing stationary
tube (after removing the original dipstick system). The stationary
tube 154 including sleeve 151 are located in the stationary tube.
Compressive nut 154 is contacted with threaded area 152 and
tightened sufficiently to retain stationary tube 154 and sleeve 151
at a fixed position. Thereafter, the inventive dipstick system can
be employed and locked into position by using the inventive bayonet
connection.
[0063] Referring now to FIG. 13, shows fluid level indicator
assembly 160 comprising a cap locking assembly 161 shown in FIGS.
1-3, 8-9 and 10 or in the aforementioned and Cross-Referenced U.S.
Patents and Patent Applications. Cap locking assembly 161 is
attached to stationary tube 162. Stationary tube 162 is staked at
163 onto engine fitting 164. Tube 162 and engine fitting 164 are
illustrated in greater detail in FIGS. 14-16.
[0064] FIG. 14 illustrates stationary tube 162 staked onto engine
fitting 164. The end of stationary tube 162 opposite from the
engine fitting 164 contains a knurled region 170. Region 170 is
provided for enhancing the bond between tube 162 and an overmolded
thermoplastic material (e.g., nylon 6,6) used in forming locking
cap assembly 161. Staking region 163 can be formed by using any
suitable machine such those supplied by EZ Crimp (e.g., containing
8 jaws and reducing the diameter of the stationary tube from 0.50
to about 0.475). The degree of diameter reduction and length of
staking region can vary widely.
[0065] In one aspect of the invention, the cap assembly is
connected to the stationary tube without the aforementioned
over-molding process. The cap assembly can be attached via a
threaded connection, glued, contacting the interior of the
stationary tube and expanding the stationary tube into contact the
coupler or cap assembly, among other methods for affixing the cap
assembly.
[0066] FIGS. 15 and 16 illustrate greater detail of tube 162 and
engine fitting 164. Tube 162 can be fabricated from any suitable
material such as ASTM J525, ASTM A513 Type 1 or 2 Alloy, among
other materials capable of withstanding staking. Engine fitting 164
can also be fabricated from any suitable material such as 12L or 15
ASTM Alloy A108, lead free alloys, among other suitable materials.
Tube 162 can be fabricated in accordance with any suitable method.
One suitable method comprises shaping or bonding the tube into a
desired configuration by employing commercially available machines
such as compression bending, rotary draw bending, among other
apparatus. Engine fitting 164 can be shaped by any suitable method
such as by a conventional screw machine operations. Engine fitting
164 can include an optional knurled region 180 for enhancing bond
formed by staking at region 163. Protuberance 181 about the
exterior of engine fitting 164 is dimensioned to receive tube 162.
Engine fitting 164 is maintained at a predetermined location with
respect to the engine's fluid reservoir by grooves 182 defined upon
the surface of the engine fitting.
[0067] Referring now to FIGS. 17A through 20B, these Figures
illustrate one aspect of the invention wherein the lugs extending
from the tube are directly attached to the tube. Such a
construction method reduces assembly costs without affecting the
effectiveness of the fluid level indicator. The tube can be
straight or a virtually unlimited array of non-linear
configurations that are tailored for a particular vehicle. The
shaft can comprise a rotating member or have a position that is
permanently affixed relative to the handle.
[0068] Referring now to FIGS. 17A through 17C, FIG. 17 shows a
fluid level indicator assembly 190 comprising tube 191 for
receiving handle 192. Assembly 190 can be linear or non-linear
depending upon the dimensions of the vehicle onto which the
assembly is attached. Handle 192 is connected to shaft 193 that
includes a fluid level measuring device (e.g., a shaft with height
markings or a separate indicator blade connected to the shaft).
Handle 192 defines slots (refer to FIGS. 18A and B) for receiving
outwardly extending lugs 194 (refer to FIGS. 19A through 20B) that
are attached directly to tube 191.
[0069] FIGS. 18A and B illustrate handle 192 illustrated in FIGS.
17A through .17C. Handle 192 defines two slots 200 for receiving
lugs 194 of tube 191. Slots 200 are non-linear include projection
201 and terminate at in a locking-seat or depression 202. Slots 200
can be configured and dimensioned to engage internal or external
extending lugs (e.g., refer to FIGS. 1-3, 9, 10 and 13). Shaft 203
is attached to handle 192 by any expedient method. Examples of such
methods comprise molding, pinning or riveting, gluing, among other
conventional attachment methods. Shaft 203 can comprise a blade or
solid member similar to device 193, wire, strand, among other
articles that can be affixed to handle 192. Fluid level measuring
device 193 is connected or attached to shaft 203 by any expedient
method such as die casting, riveting, welding, among other
conventional attachment methods. Handle 192 defines gripping
regions 204 that enhance the ability of a vehicle operator to twist
the handle for removal from the tube. Gripping regions 204 can
comprise any suitable configuration such as the T illustrated in
FIGS. 17A through 18B, knurled, among other protuberances that
enhance gripping. A gasket or grommet 205 is received within the
base of handle 192. The gasket 205 can be received within the base
of handle 192 and have any suitable configuration such as
illustrated previously in FIGS. 1-7 and 10. The gasket 205 contacts
the tube 191 in at least one area such as tube end face, an inner
wall of the tube and exterior wall of the tube.
[0070] FIGS. 19A through 19E illustrate tube 191 of assembly 190
illustrated in FIGS. 17A through 17C. Tube 191 includes lugs 194A
and B that are connected directly to tube 191. These lugs can be
affixed or connected to the tube by any expedient method such as
projection welding, self-clinching, drilling and filling with a
fastener, among other conventional methods for connecting a lug. As
described above, lugs can be either inwardly or outwardly
extending. Alternatively, the lugs can be replaced with a suitable
protuberance wherein the protuberance engages the slotted handle in
a manner similar to a lug and locks the handle to the tube. In the
case of an inwardly extending protuberance, the protuberance can be
formed by creating an indent (e.g., by forcing a punch or other
tool partially through the wall of the tube).
[0071] The configuration of tube 191 can vary widely depending upon
the vehicle in which the tube is attached. If desired, the first
end of the tube (i.e., the end adjacent lugs 194) can be flared to
have a diameter that is greater than the remainder of the tube, or
a coupler having a relatively large diameter can be compression fit
into the first end. The second end of tube 191 can also include
flared areas such as 300 and 301. These areas can be employed for
retaining the tube at a predetermined location while shaping the
tube, retaining a compression fit engine fitting, among other
uses.
[0072] Referring now to FIGS. 20A and 20B, these Figures illustrate
lug 194 that can be affixed to tube 191 of the assembly illustrated
in FIGS. 17A through C. Lug 194 defines a shank portion 400 and a
head portion 401. The head portion 401 has an enlarged diameter
relative to the shank portion 400. While FIGS. 20A and 20B
illustrate one lug, lugs can have any suitable configuration and
cross-section (e.g., circular, oval, hexagonal, among others). The
dimension and size of the lugs are selected so as to engage the
slots defined in the handle.
[0073] The invention has been described with reference to certain
aspects. These aspects can be employed alone or in combination.
Modifications and alterations will occur to others upon a reading
and understanding of this specification. Although the described
aspects discuss plastic as one material of construction, it is
understood that other materials can be used for selected components
if so desired. It is understood that mere reversal of components
that achieve substantially the same function and result are
contemplated, e.g., the seal and locking features can be achieved
by differently configured seals and/or lug and slot arrangements
without departing from the present invention. It is intended to
include all such modifications and alterations insofar as they come
within the scope of the appended claims or the equivalents
thereof.
* * * * *